The present invention relates to a photograph device for printing an image on photographic paper by exposing the photographic paper as a photosensitive material by means of an image display device such as a digital micromirror device (hereinafter referred to as DMD) or a reflection-type liquid crystal display device.
Conventionally, various photograph printing devices each equipped with a DMD as means for displaying images have been proposed. The DMD is, as shown in FIGS. 6(a) and 6(b), a device equipped with a plurality of micromirrors 51 which are extremely small. Each micromirror 51 is installed on a substrate 53 through a post 52, and is swingable with respect to the substrate 53. The DMD is arranged so as to control inclination of the micromirrors 51 in accordance with inputted image data so as to change directions of reflection of light, whereby exposure of photographic paper is controlled.
In other words, during exposure of the photographic paper, as shown in FIG. 6(a), the micromirror 51 is inclined clockwise as viewed in the figure through an angle of xcex8 (inclined through an angle of xe2x88x92xcex8) with respect to a surface of the substrate 53, thereby reflecting the light from a light source toward the photographic paper. On the other hand, during non-exposure of the photographic paper, as shown in FIG. 6(b), the micromirror 51 is inclined anti-clockwise as viewed in the figure through an angle of xcex8 (inclined through an angle of +xcex8) with respect to the surface of the substrate 53, thereby reflecting the light from the light source in a direction different from the direction toward the photographic paper. Incidentally, the micromirror 51 exhibits either the state shown in FIG. 6(a) or that shown in FIG. 6(b) when the power source of the device is in an ON state or in an OFF state.
Photograph printing devices using such DMDs are disclosed by the Japanese Publications for Laid-Open Patent Applications No. 262582/1996 (Tokukaihei 8-262582, Date of Publication: Oct. 11, 1996), No. 160140/1997 (Tokukaihei 9-160140, Date of Publication: Jun. 20, 1997), No. 160141/1997 (Tokukaihei 9-160141, Date of Publication: Jun. 20, 1997), No. 164723/1997 (Tokukaihei 9-164723, Date of Publication: Jun. 24, 1997), and No. 164727/1997 (Tokukaihei 9-164727, Date of Publication: Jun. 24, 1997). Any one of these prior art publications disclose an arrangement wherein, as shown in FIG. 7, during exposure of photographic paper 61, micromirrors (not shown) provided in a DMD 63 are inclined through a predetermined angle with respect to a surface of a substrate so that light from a light source 62 is reflected by the DMD 63 in a direction toward the photographic paper 61, while during non-exposure of the photographic paper 61 the micromirrors are inclined with respect to the substrate surface so that the light from the light source 62 is reflected in a direction toward a light absorbing plate 64 (an optical path is directed toward an OFF side).
Furthermore, a condenser lens 65 is provided between the light source 62 and the DMD 63 so as to converge the light from the light source 62 and project it onto the DMD 63. The condenser lens 65 is in a shape such that, to avoid interference with a part of light which has been reflected by the DMD 63 and is going toward the photographic paper 61, a portion thereof which would cause the foregoing interference is cut out. A broken line in the figure indicates the portion (the cutout portion of the condenser lens 65 which would cause interference.
Incidentally, though not shown in the figure, optical components such as a light adjusting filter, a heat-resistant filter, and a balance filter may be provided as required, between the light source 62 and the DMD 63. The light adjusting filter is to take out color lights R (red), G (green), and B (blue) from white light emitted by the light source 62. The heat-resistant filter is to cut off infrared, and the balance filter is to perform shading correction so that light is projected on the surface of the DMD 63 with a uniform illuminance. On the other hand, between the DMD 63 and the photographic paper 61, a projection lens, a negative film, or the like is provided as required.
However, to realize the foregoing conventional arrangement wherein the light from the light source 62 is made incident obliquely with respect to the DMD 63, it is necessary to arrange the optical components so that light is made. incident to the DMD 63 at a certain angle of incidence. Therefore, a space required to dispose the optical components becomes larger, thereby causing the device to become bulkier.
Incidentally, for example, an arrangement wherein a distance between the light source 62 and the DMD 63 is shortened so as to avoid the foregoing problem may be devised. However, since there are when necessary provided the foregoing optical components between the light source 62 and the DMD 63, there are limits to the shortening of the distance between the light source 62 and the DMD 63. Furthermore, the same also applies to the shortening of the distance between the DMD 63 and the photographic paper 61. Therefore, it is impossible to make the device drastically smaller by this method.
The object of the present invention is to provide a photographic printing device which is equipped with an image displaying device such as a DMD and is formed remarkably compact.
To achieve the foregoing object, a photograph printing device of the present invention, which is a photograph printing device for printing an image by exposing a photosensitive material, is characterized by comprising (i) a light source, (ii) light modulating means for modulating light from the light source at each pixel in accordance with image data, and (iii) an optical element for guiding the light from the light source to the light modulating means, while guiding light modulated by the light modulating means to the photosensitive material, the optical element being positioned in an optical path between the light source and the light modulating means.
With the foregoing arrangement, light from the light source is projected through the optical element to the light modulating means, which modulates the light in accordance with image data. Among the light modulated, the light reaching the optical element is guided by the optical element to the photosensitive material. As a result, an image in accordance with the image data is printed on the photosensitive material.
More specifically, light projected from the optical element to the light modulating means, after being modulated by the light modulating means in accordance with the image data, goes through the substantially same region as the optical path region of the incident light, thereby again entering the optical element. Therefore, the angle of incidence and the angle of outgoing of light at the light modulating means do not have to be made greatly different from each other, unlike in the conventional arrangements, and hence a large space is not required for arrangement of the constituent components. In other words, as compared with the foregoing arrangement, the space for arrangement of the constituent components can be made smaller, resulting in that the device can be made remarkably compact as compared with the conventional cases.
For a fuller understanding of the nature and advantages of the invention, reference should be made to the ensuing detailed description taken in conjunction with the accompanying drawings.